Jump to content

Bad Lifters

Sean D

By Sean D
in Troubleshooting & Recalls

Recommended Posts

Sean D Enthusiast

Sean D

Posted
Posted

I have a 2015 Silverado 5.3 that had a misfire on 7th cylinder. Ended up taking it to the dealer and they said I had four bad lifters. Truck has 88k they ended up warranting the work. Has anyone else have this issue in here seems like a known issue now that’s I’m researching..

CamGTP Senior Enthusiast

CamGTP

Posted
Posted

It's a very well known issue. This stuff dates all the way back to vehicles made since 2005 when this system first started.

 

2014+ trucks is either the lifters or injector issue for bad misfire problems.

Grumpy Bear Senior Enthusiast

Grumpy Bear

Posted
Posted
2 hours ago, CamGTP said:

It's a very well known issue. This stuff dates all the way back to vehicles made since 2005 when this system first started.

 

2014+ trucks is either the lifters or injector issue for bad misfire problems.

Cameron:

 

Question. AFM Lifter failures fall into three groups. Defects in lifter materials/craftsmanship OR oil related. That is lack of oil maintenance in that the screen plugs partially and mistimes a switch physically breaking the lifter pins OR oil aeration. Any idea on the percentage of failures to each condition? 

 

Secondly, is it not also true that AFM motor type lifter failures also happen to NON-AFM cylinders? Primary failure in the check ball/spring and yet are attributed as AFM lifter failures? 

 

You seem to have more unbias knowledge on this topic than most. Your thoughts please? 

 

Thank you in advance. 

 

Grumpy

CamGTP Senior Enthusiast

CamGTP

Posted
Posted

I think the idea and craftsmanship of the AFM system is good, I mean they had to come up with something for the CAFE deal. The materials and for some, poor care was a downfall. Just the way the AFM lifter is activated was just asking for an issue to happen at one point. Solenoid failures, poor oil conditions that hurt parts and plug filters. Having a spring system on a lifter that is constantly working on and off in city driving and so on.

 

I couldn't even guess the percentage of each type of failure but I've always seen the same type of problem. The lifter itself is almost always collapsed and the VLOM is second in line for issues.

 

The regular lifters can for sure have the ball/spring be an issue. Could make them really noisy as well but yet they will still run making noise forever it seems. Camshaft damage will take out the rollers too. Not sure how you'd ever be able to prevent that when it's a metal quality issue.

 

I dunno if that helped answer much, it's past my bed time lol.

Beer Belly Enthusiast

Beer Belly

Posted
Posted

I had 1,3,5 and 7 replaced. CEL and Stability Control lit up, rough running truck, straightened up and ran fine on the way to the dealer. Codes pulled, cyl. 7 had 6,900 misfires, could not duplicate and sent me on my way. One week later, happened again, made it to the dealer and left it running for 45 minutes waiting for them to open their doors, stunk up the entire lot running like poop. Same codes, this time replaced the Lifters. Funny thing is, the tech on the first trip told me he was going to replace all the lifters, but then I got the call saying the GM refused being the truck was running fine despite the codes.

Grumpy Bear Senior Enthusiast

Grumpy Bear

Posted
Posted
11 hours ago, CamGTP said:

I think the idea and craftsmanship of the AFM system is good, I mean they had to come up with something for the CAFE deal. The materials and for some, poor care was a downfall. Just the way the AFM lifter is activated was just asking for an issue to happen at one point. Solenoid failures, poor oil conditions that hurt parts and plug filters. Having a spring system on a lifter that is constantly working on and off in city driving and so on.

 

I couldn't even guess the percentage of each type of failure but I've always seen the same type of problem. The lifter itself is almost always collapsed and the VLOM is second in line for issues.

 

The regular lifters can for sure have the ball/spring be an issue. Could make them really noisy as well but yet they will still run making noise forever it seems. Camshaft damage will take out the rollers too. Not sure how you'd ever be able to prevent that when it's a metal quality issue.

 

I dunno if that helped answer much, it's past my bed time lol.

Always helpful. Could have answered anytime so thanks for the extra and sorry you missed some sleep. Not intended but apricated. Lot's to sift through here. 

 

I've been thinking about the cam lobe damage after reading a article in another thread some months back that was talking about these timing failures. How the system is designed to collapse AND EXTEND the lifter on the base circle. When a timing error occurs wherein the lifter extended on the open ramp the forces are HUGE. I have a picture similar to piston assisted valve closing type failures. Often the pushrod is bend as well, yes? Wouldn't make much difference what the metallurgy was in that case. Pretty much what would happen with aeration or screen plugging. In that case what looks like a metals issue is really a lubrication/lubrication maintenance issue.

 

I've read reports of bad batches of lifter but mostly pre 2014 although it can happen anytime, granted. I've even seen some liters, which are a centerless ground product, that looked like they should have never made it in a motor. A QC issue, agreed?

 

My guess would be that the clock in the PCM and solenoid system doesn't get 'confused' as to where it is in it's cycle, unless of course there is a cam/crank position sensor failure. Miss timed events then would have to be hydraulic issues. That is, while oil is incompressible, thus the reason for it's use, entrained air, aeration, or cavitation voids, as when oil is forced through a screen at a rate faster than it can pass, as would be the case if say 75% of the screen were plugged (debris/varnish) delay the lifter EXTENTION ONLY as the screens on the inlet side. Whew, long sentence, sorry. Hope it made sense. Does in my mind but  you know well the trouble I have getting thought on paper in a way others understand.

 

I suppose it could also happen in the event of a solenoid sticking? That is it gets its signal on time but 'varnish' delays application a nanosecond? Possible I guess. A solenoid is not direct acting as a gear would be. 

 

That same article suggested shorter OCI's. I've seen this before with the 2.4L motor ring issues where in those motors had the OLM reprogramed for shorter OCI's. Terrain? Verano? I'm starting to ramble...….

 

It would seem then that a good number of failures are oil maintenance related. Even when then look materials related. And yes some design, metals, QC issues, enough to keep the waters muddy.

 

One issue confuses me however and that is aeration. I normally think of this as a windage issue in high RPM motors (towing?) but there is allot of windage control designed into these motors. Oils have antifoam agents. Still those can be overwhelmed with fuel/water/antifreeze contamination. Perhaps less confused that I thought now I see in on paper. :) Again oil maintenance.  Hummm.

 

On 3/22/2020 at 10:44 AM, Sean D said:

I have a 2015 Silverado 5.3 that had a misfire on 7th cylinder. Ended up taking it to the dealer and they said I had four bad lifters. Truck has 88k they ended up warranting the work. Has anyone else have this issue in here seems like a known issue now that’s I’m researching..

Yes the issue is real. What's in question is how much control do you have over it? Perhaps I should say how much you HAD over it. Nothing is more hotly debated than oil maintenance. I'm not about to question you about this. I will share with you that I'm know as an 'over maintenance' sort. I replaced the screen to the VLOM somewhere between 50 and 75K and still found debris in it. I've added it to my list of regular replacement items. The ones under the solenoids on the VLOM are not serviceable. 

 

All that said. It isn't as common as it looks if you look at the entire population of motors produced. 

 

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Latest Articles

  • Posts

    • anthony2558
      Would this CV Shaft be bad?

      By anthony2558 · Posted

      Would this be normal or a worn CV Shaft? 51K miles 3.5" lift? Boots are intact and no visible leaks showing. Attached is a the video I took. Thanks   https://youtu.be/ZnW7PPRmjJY?feature=shared
    • Jsdirt
      2010 Avalanche 5.3 not running correctly after engine swap.

      By Jsdirt · Posted

      If everything checks out at the MAF, then the MAF is BAD, new or not.   You don't need a signal generator to troubleshoot this. PCM needs ALL powers and ALL grounds able to light a halogen headlight bulb - if it can light the bulb bright, then the wiring is good enough to run the PCM.   Best thing you can do for yourself is spend some time here: scannerdanner.com - Check out all his YouTube videos on similar issues. If you decide to subscribe it's the best bang-for-buck ratio in the automotive world, hands-down. He's got TONS of free vids on YouTube, too.
    • Tyler Gibbs
      PF63 Oil Filters Going Away?

      By Tyler Gibbs · Posted

      You got that Hengst D110??
    • contrabombarde
      2010 Avalanche 5.3 not running correctly after engine swap.

      By contrabombarde · Posted

      Yes, I used my multimeter to probe all of the wires at the MAF, both with the sensor connected, sensor disconnected, key on engine off, key on engine running, etc etc etc. I probed all of the wires again at the PCM, at the connectors, etc. All voltages are what they should be according to the service manual/wiring diagrams. All grounds are good, less than 20 millivolts from the battery negative under load. Both at the connector of the MAF, at the PCM connector etc.      I know this throws a pretty big wrench into things, but this truck was acting up before the swap. I don't have very much information, if any on what was causing it, but if you cleared all of the dtcs it would do the same thing where it would crank, fire, then die. And it would do the same thing a dozen or so times, and eventually it would start and run, but the difference is that it would run and actually be drivable. Whereas now if you can drive it at all, it goes into reduced power mode almost immediately, and even then it's not running correctly. When you come to a stop at a light it stumbles down to for 500 RPM before catching itself and returning to the smooth idle. And if you go more than about 50% throttle then it immediately goes back to doing the misfire thing.    Like I said, I know that throws a wrench into things, and unfortunately I was not able to pull any data or anything like that before I did this work, so I don't have much to go on.    I'm trying to not fixate on one particular thing as the cause of the problem, but it seems like all avenues are pointing me towards the PCM. Like I said I have tested the wiring extensively (see above), and during cranking the sensor does produce seemingly legitimate values at least according to my multimeter, but as soon as the engine fires those values quickly descend into gibberish. I've tried it with multiple different known working sensors, I have done literally every test I can think of multiple times on the wiring (probing the signals, probing the pins with the sensors unplugged, probing the pins at the PCM, voltage drop, voltage drop under load, continuity, ohms, and double-checking everything against the wiring diagrams/ proper values in the service data.)    Another thing that pushes me towards a possible PCM failure is, I have noticed in troubleshooting a little bit taking a break and coming back, that when I leave the truck to sit for a while and cool off, it starts and runs smoothly when I first start it up. However once it warms up. It starts having problems. For example, when I went out to the truck this morning after it had been sitting overnight, I was actually able to drive it down the block. And then once I got on the throttle a Little bit after going about a thousand ft, it started misfiring again. I pulled it back into the driveway, shut it down, and started it back up. It idled smoothly. As soon as I touched the throttle it did the misfire thing again. From then on as soon as I started it it would misfire. I shut the truck off and went to go get a coffee and do a bit more research. When I came back out I started the truck up and it immediately went into the smooth idle. After a couple of minutes of playing around with it, it would not idle smoothly anymore. Let it sit a couple of hours, rinse and repeat. This makes me think with temperature change something is going wrong inside the PCM. I have the PCM out of the 2007 donor vehicle and I'm thinking of getting a one-day subscription to the ACDelco programming service to try and program that and see if it helps.   Like I said, I'm really trying to not fixate myself on one potential cause, but it seems everything is pointing me towards PCM failure. I would really like to try to confirm that, but unfortunately I don't have an oscilloscope or a signal generator to do the GM service procedure where you feed 5 khz into the signal pin. 
    • Jsdirt
      2010 Avalanche 5.3 not running correctly after engine swap.

      By Jsdirt · Posted

      Ahh, sorry about that - I got some bad info. Newdude is correct. That's what I get for working 13 hours straight ... on my "vacation", lol.   Should've checked the files I had instead of the internet.   Anyway ... this is GREAT news, since this would've been an absolute friggin nightmare to get working.   I don't think the lack of VVT is causing this - you've got another issue. Wiring, I'm betting.   I'm telling you right now, your computer isn't bad. If it worked before the swap, it's working now. You need to do some more (better) diagnostics and figure out exactly what you're missing. Did you test every wire directly at the MAF? Have 5V reference? Ground? If you're reading ZERO g/s, your Hz isn't much use - it's going to be the wrong value anyway. The MAF is not working, and you need to find out WHY.   I got this off the net, so VERIFY first: Pin A: Black (BLK) wire, Circuit 552, serves as the Sensor Return (Ground).  Pin B: Tan (TAN) wire, Circuit 472, carries the Intake Air Temperature (IAT) signal.  Pin C: Yellow (YEL) wire, Circuit 492, is the primary MAF Sensor Signal output to the PCM. Pin D: Pink (PNK) wire, Circuit 339 or 539, provides Ignition 1 Voltage (Power).  Pin E: Tan/Black wire, Circuit 552 or similar, often associated with the Intake Air Temperature ground or signal return.  Global-A list: https://postimg.cc/KKJnQC85    

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...